JP7098670B2 - Electronic modules and electronic devices - Google Patents

Description

The present invention relates to an electronic component mounting technique.

Electronic devices such as digital still cameras and digital video cameras are required to be miniaturized, and along with this, printed wiring boards are also required to be miniaturized. A plurality of electronic components are mounted on the printed wiring board. In order to reduce the size of the printed wiring board, it is necessary to use small electronic components. Electronic components are two-terminal chip components such as capacitors, inductors or resistors. Electronic components have two electrodes, each located at two longitudinal ends. Each electrode of the electronic component is soldered to the land of the printed wiring board.

In order to reduce the size of the printed wiring board, it is necessary to narrow the distance between two electronic components adjacent to each other in the longitudinal direction among the plurality of electronic components. Therefore, when a plurality of electronic components are mounted on a printed wiring board at high density, it is necessary to prevent two adjacent electronic components from being short-circuited by soldering.

Patent Document 1 describes mounting chip components on a substrate at high density. Further, Patent Document 1 describes that in order to prevent the chip component from sinking, a spacer is arranged between the chip component and the substrate to reduce the amount of solder overhang on the side surface of the chip component. ..

Japanese Unexamined Patent Publication No. 7-74450

Electronic components are becoming smaller than before, and further miniaturization is expected in the future. As described above, when the electronic component is further miniaturized, when the spacer is arranged between the electronic component and the substrate as in Patent Document 1, the spacer also needs to be further miniaturized. However, it has become difficult to form a small spacer in accordance with the miniaturization of the electronic component and to position the small spacer between the electronic component and the substrate with high accuracy.

An object of the present invention is to enable high-density mounting of electronic components on a printed wiring board while ensuring the bonding strength between the electronic components and the printed wiring board.

The present invention includes a first chip component and a second chip component, each of which is provided with a first electrode and a second electrode at the end in the longitudinal direction, and has a length in the longitudinal direction of L2 and a length in the lateral direction of W. The insulating substrate, the solder resist film having an opening provided on the insulating substrate, and the first land and the second electrode exposed at the opening are bonded to the first land and the second electrode, respectively, via solder. An electronic module comprising a printed wiring board comprising two lands, wherein the first chip component and the second chip component are along the longitudinal direction so that the longitudinal directions of the first chip component and the second chip component coincide with each other. When the inductors or capacitors arranged adjacent to each other, the distance Rx between the first chip component and the second chip component in the longitudinal direction is W or less, and the length of the opening in the longitudinal direction is L1. L1 and L2 satisfy 0.894≤L2 / L1≤1.120, the length of the first land in the longitudinal direction is _LiA , the length of the second land is _LiB , and the first electrode. When the thickness of the solder on the side end surface of the second electrode is LOA and the thickness of the solder on the side end surface of the second electrode is _{LOB, 0.183 ≤ L OA / L iA} ≤ 0.309 and 0.183 ≤ L. It is an electronic module characterized by satisfying _OB / _LiB ≤ 0.309.

Further, the present invention includes a first electrode and a second electrode at the end in the longitudinal direction, respectively, and the length in the longitudinal direction is L2 and the length in the lateral direction is W, the first chip component and the second chip component. A first land bonded to the insulating substrate, a solder resist film having an opening provided on the insulating substrate, and the first electrode and the second electrode exposed at the opening via solder, respectively. An electronic module comprising a second land and a printed wiring board, wherein the first chip component and the second chip component are oriented in the longitudinal direction so that the longitudinal directions of the first chip component and the second chip component coincide with each other. It is a resistor arranged adjacently along the same direction, the distance Rx between the first chip component and the second chip component in the longitudinal direction is W or less, and the length of the opening in the longitudinal direction is L1. When, the L1 and the L2 satisfy _0.894 ≦ L2 / L1 ≦ 1.120, the length of the first land in the longitudinal direction is _LiA , the length of the second land is LiB, and the first land is the first. When the thickness of the solder on the side end surface of the electrode is L _OA and the thickness of the solder on the side end surface of the second electrode is L _OB , 0.177 ≤ L _OA / L _iA ≤ 0.309 and 0.177 ≤ It is an electronic module characterized by satisfying L _OB / _LiB ≦ 0.309.

According to the present invention, it is possible to mount an electronic component on a printed wiring board at a high density while ensuring the bonding strength between the electronic component and the printed wiring board.

It is explanatory drawing of the electronic device which concerns on 1st Embodiment. (A) is a schematic diagram of a joint structure of an electronic component and a printed wiring board according to the first embodiment. (B) is a perspective view of a part of an electronic component and a printed wiring board according to the first embodiment. (A) is a plan view of a part of the printed wiring board according to the first embodiment. (B) is a plan view of a part of the printed circuit board according to the first embodiment. It is a graph which shows the simulation result in 1st Embodiment. It is a perspective view of the electronic component which concerns on 2nd Embodiment, and a part of the printed wiring board. It is a graph which shows the simulation result in 2nd Embodiment. It is a schematic diagram of the joint structure of the electronic component and the printed wiring board which concerns on 3rd Embodiment. It is a graph which shows the simulation result in 3rd Embodiment. FIG. 3 is a plan view of a part of a printed circuit board including three electronic components according to the first embodiment.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 1 is an explanatory diagram of a digital camera 600, which is an image pickup device as an example of an electronic device according to a first embodiment. The digital camera 600 is a digital camera with interchangeable lenses, and includes a camera body 601. A lens barrel 602 including a lens 621 can be attached to and detached from the camera body 601. The camera body 601 includes a housing 611, a sensor module 700, an image processing module (not shown), and a wireless communication module 100 which is a printed circuit board. The wireless communication module 100 is an example of an electronic module. The wireless communication module 100, the sensor module 700, and the image processing module (not shown) are provided in the housing 611.

The sensor module 700 has an image sensor 701 and a printed wiring board 702 on which the image sensor 701 is mounted. The image sensor 701 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor. The image sensor 701 has a function of converting light incident through the lens barrel 602 into an electric signal. The image processing unit includes an image processing device. The image processing device is, for example, a digital signal processor. The image processing device has a function of acquiring an electric signal from the image sensor 701, performing a process of correcting the acquired electric signal, and generating image data.

The wireless communication module 100 performs wireless communication in, for example, a GHz band. The wireless communication module 100 preferably has a transmission function, and in the present embodiment, it has a transmission / reception function. The wireless communication module 100 includes a printed wiring board 5 including an antenna 33, and a wireless communication IC 31 which is an example of a semiconductor component mounted on the printed wiring board 5. Further, the wireless communication module 100 has a connector 32 mounted on the printed wiring board 5 and electrically connected to the wireless communication IC 31 by the wiring of the printed wiring board 5. The wireless communication IC 31 transmits or receives image data by wirelessly communicating with an external device such as a PC, a smartphone, or a wireless router via the antenna 33. That is, the wireless communication IC 31 modulates a digital signal indicating image data and transmits it from the antenna 33 as a radio wave having a communication frequency of a wireless standard. Further, the wireless communication IC 31 demodulates the radio wave received by the antenna 33 into a digital signal indicating image data. A shield case 34 is arranged between the housing 611 and the wireless communication module 100 so as to face the semiconductor components and electronic components mounted on the printed wiring board 5.

The wireless communication module 100 has electronic components 1A, 1B, 1C mounted on the printed wiring board 5. Each electronic component is a two-terminal chip component. The size of each electronic component in plan view is 0603 size such as 0603 size which is 0.6 mm × 0.3 mm, 0402 size which is 0.4 mm × 0.2 mm, or 0201 size which is 0.25 mm × 0.125 mm. The following are suitable. From the viewpoint of miniaturizing the electronic components, the size of each electronic component is more preferably 0402 size or less. The notation of 0603 size, 0402 size, 0201 size and the like conforms to the size notation method (mm standard) of electronic parts in the Japanese Industrial Standards (Japanese Industrial Standards).

FIG. 2A is a schematic diagram of a joint structure between the electronic components 1A and 1B according to the first embodiment and the printed wiring board 5. FIG. 2B is a perspective view of the electronic component 1A according to the first embodiment and a part of the printed wiring board 5. FIG. 2B illustrates the state before the electronic component 1A is mounted on the printed wiring board 5 for convenience of explanation. Although FIG. 2B shows only the electronic component 1A, the electronic components 1B and 1C also have the same arrangement with respect to the printed wiring board 5.

As shown in FIGS. 2A and 2B, the electronic components 1A and 1B are provided at the first end of the two ends of the base 2 and the base 2 in the longitudinal direction X, respectively. It includes an electrode 3 which is a first electrode and an electrode 4 which is a second electrode provided at a second end portion. The electronic component 1A as the first chip component and the electronic component 1B as the second chip component are arranged adjacent to each other along the longitudinal direction so that the longitudinal directions coincide with each other.

The printed wiring board 5 includes an insulating substrate 10, a conductor pattern 70 which is a first conductor pattern, and a conductor pattern 80 which is a second conductor pattern provided on the main surface 110 of the insulating substrate 10. The conductor patterns 70 and 80 are metal foils such as gold, silver and copper. The conductor pattern 70 and the conductor pattern 80 are arranged on the main surface 110 at intervals in the longitudinal direction X. The conductor patterns 70 and 80 are formed by a manufacturing method such as a subtractive method in which a copper foil is attached to the main surface 110 of the insulating substrate 10 and unnecessary portions are dissolved and removed with a chemical to leave a necessary conductor pattern. To. The printed wiring board 5 has a solder resist film 6 made of a solder resist provided on the main surface 110.

FIG. 3A is a plan view of a part of the printed wiring board 5 in the first embodiment. As shown in FIG. 3A, the solder resist film 6 is formed with an opening 61 so as to expose a part of the conductor pattern 70 and a part of the conductor pattern 80. In the conductor pattern 70, the portion exposed by the opening 61 is the land 7, which is the first land. In the conductor pattern 80, the portion exposed by the opening 61 is the land 8 which is the second land. Lands 7 and 8 are arranged at intervals in the longitudinal direction X. Therefore, the portion 111 between the land 7 and the land 8 on the main surface 110 of the insulating substrate 10 is exposed at the opening 61.

In the conductor pattern 70, the end portion 71 on the side facing the conductor pattern 80 in the longitudinal direction X is exposed without being covered with the solder resist film 6, and the end portion 72 on the side opposite to the end portion 71 is the solder resist film 6. It is covered. This makes it possible to prevent the conductor pattern 70 from peeling off from the main surface 110. In the conductor pattern 80, the end portion 81 on the side facing the conductor pattern 70 in the longitudinal direction X is exposed without being covered with the solder resist film 6, and the end portion 82 on the side opposite to the end portion 81 is the solder resist film 6. It is covered. This makes it possible to prevent the conductor pattern 80 from peeling off from the main surface 110.

In the first embodiment, in the conductor pattern 70, the two ends 73 and 74 in the lateral direction Y orthogonal to the longitudinal direction X are covered with the solder resist film 6. This makes it possible to more effectively prevent the conductor pattern 70 from peeling off from the main surface 110. In the conductor pattern 80, the two ends 83, 84 in the lateral direction Y are covered with the solder resist film 6. This makes it possible to more effectively prevent the conductor pattern 80 from peeling off from the main surface 110. As shown in FIG. 2A, the electrode 3 and the land 7 are joined by a solder joint portion 9 containing solder. The electrode 4 and the land 8 are joined by a solder joint portion 9 containing solder.
The thickness of the solder resist film is not particularly limited, but it is preferable that the upper surface of the solder resist film is 5 μm or more higher than the upper surfaces of the lands 7 and 8. The presence of the solder resist at a position higher than the upper surfaces of the lands 7 and 8 prevents the electronic components from sinking due to the so-called lift-up effect, and sufficiently accommodates the solder between each land and the electrodes of the electronic components. Because it can be done. If the solder can be sufficiently accommodated in the recess in the opening of the solder resist film, the length of the solder protruding from the side end surface of the electrode can be reduced.

In the first embodiment, the electronic components 1A, 1B, and 1C are chip components that are inductors or capacitors. As shown in FIG. 2B, the electrode 3 has a side end surface 11 that is located on the outermost side in the longitudinal direction X and intersects the longitudinal direction X, and the electrode 3 is located on the outermost side in the lateral direction Y. Includes sides 13, 14 and, which intersect with. That is, the normal to the side end surface 11 is oriented in the longitudinal direction X, and the normal to the side surfaces 13 and 14 is oriented in the lateral direction Y. Further, the electrode 3 has a bottom surface 17 and an upper surface 18. Each surface 11, 13, 14, 17, 18 may be a flat surface or a curved surface. The electrode 4 has a side end surface 12 that intersects the longitudinal direction X, which is located on the outermost side when viewed along the longitudinal direction X, and the electrode 4 is located on the outermost side when viewed along the lateral direction Y. Includes sides 15, 16 intersecting with. That is, the normal to the side end surface 12 is oriented in the longitudinal direction X, and the normal to the side surfaces 15 and 16 is oriented in the lateral direction Y. Further, the electrode 4 has a bottom surface 19 and a top surface 20. Each surface 12, 15, 16, 19, 20 may be a flat surface or a curved surface. As described above, when the electronic component is a chip component of an inductor or a capacitor, solder adheres to the electrodes 3 and 4 on each of the five surfaces.

Here, as shown in FIG. 1, in order to mount a plurality of electronic components arranged close to each other on the printed wiring board 5 at high density, it is necessary to narrow the distance between the two adjacent electronic components 1. On the other hand, as a method of mounting each electronic component (1A, 1B, 1C) on the printed wiring board 5, a method by SMT (Surface Mount Technology) including a printing process, a mounting process, and a reflow process is used.

In the printing process, a solder paste (not shown) containing solder particles and flux is applied onto lands 7 and 8 shown in FIG. 2 (b) by a screen printing method using a mask made by drilling holes in a thin metal plate such as stainless steel. Supply. In the mounting process, the electronic component 1A supplied by the feeder or the like is sucked by the suction nozzle provided on the head. After that, the electronic component 1A adsorbed by the suction nozzle is positioned on the lands 7 and 8 on which the solder paste is arranged, the suction nozzle is lowered, and the electronic component 1A is placed on the solder paste.

In the reflow process, the solder paste is melted by heating, and the electronic components 1A and the lands 7 and 8 are soldered. During this reflow process, the molten solder crawls up the side end surface 11 of the electrode 3 of the electronic component 1A and the side end surface 12 of the electrode 4. This ensures the strength of the joint.

However, if the length of the molten solder projecting outward from the side end surface of the electrode is too long, a short-circuit defect occurs between two electronic components arranged close to each other. By arranging a spacer at the bottom of the electronic component, it is possible to prevent the electronic component from sinking and control the amount of solder that protrudes from the side surface of the electrode to the outside. It is difficult to place a small spacer on a printed wiring board.

It is also conceivable to adjust the solder paste to an amount that does not cause short-circuit defects, that is, to reduce the holes in the mask used for screen printing. However, if the holes in the mask are made smaller, the viscosity of the solder paste makes it easier for the solder paste to remain in the holes in the mask. This may result in a shortage of solder paste supply, and there is a limit to adjusting the amount of solder paste. In particular, not only small electronic parts having a size of 0402 or less, but also large IC parts, connector parts, and the like are mounted on the printed wiring board, and bonding strength is required for these large parts as well. In screen printing, the solder paste used for joining electronic parts, IC parts, connector parts, and the like is collectively supplied onto a printed wiring board using one mask. Therefore, it is difficult to finely adjust the amount of solder paste with such a mask so as to be suitable for small electronic components.

Therefore, in the first embodiment, the length of the opening 61 of the solder resist film 6 in the longitudinal direction X is set to be substantially the same as the length of the electronic components 1A, 1B, 1C in the longitudinal direction X. Specifically, when the length of the opening 61 in the longitudinal direction X is L ₁ and the length of the electronic components 1A, 1B, 1C in the longitudinal direction X is L ₂ , 0.894 ≤ L ₂ / L ₁ ≤ The opening 61 is formed so as to satisfy the relationship of 1.120. The thickness of the solder resist film 6 is, for example, 10 μm or more and 35 μm or less. When viewed in a plan view, the side end faces 11 and 12 of the electrodes 3 and 4 of the electronic components 1A, 1B and 1C and the outer ends of the lands 7 and 8 are almost aligned, so that the solder joint portion 9 is shown in FIG. 2 (a). ), It has a filletless structure.

When the size of the electronic components 1A, 1B, 1C is 0402, the nominal value of the length L2 of the electronic components 1A, _1B , 1C in the longitudinal direction X is 0.4 mm. Therefore, the reference value of the length L1 of the opening 61 in the longitudinal direction X is set to 0.4 mm, which is the same as the nominal value of the electronic components _1A , 1B, and 1C. The tolerance of the opening 61 in the length L ₁ in the longitudinal direction X with respect to the reference value of 0.4 mm, that is, the manufacturing error is about ± 0.025 mm in the above-mentioned subtract method. Further, the tolerance of the length L ₂ of the electronic components 1A, 1B, 1C in the longitudinal direction X is about ± 0.02 mm. Therefore, (0.4-0.02) / (0.4 + 0.025) ≈0.894 is the _lower limit of L2 _/ L1. Further, (0.4 + 0.02) / (0.4-0.025) _≈1.120 is the _upper limit of L2 / L1. When L2 / L1 is 1.00 or less, the above-mentioned lift-up effect is likely to be exhibited.

As described above, by making the length L1 of the opening 61 formed in the solder resist film 6 in the longitudinal direction X substantially the same as the length L2 of the electronic components _1A , _1B , 1C in the longitudinal direction X, the electrode 3 , The solder resist film 6 is present in the vicinity of 4. As a result, when the molten solder wets and spreads to the lands 7 and 8 in the reflow process, it does not get wet and spread outside the electronic component in a plan view. That is, since the molten solder stays on the lower surface of the electronic component, the molten solder exerts a force to lift the electronic component by surface tension. Therefore, it is possible to prevent the electronic components 1A, 1B, 1C from sinking into the lands 7 and 8, and it is possible to accommodate the molten solder between the electronic components 1A, 1B, 1C and the lands 7, 8. Further, by arranging the opening 61 of the solder resist film 6 so as to surround the printed wiring board 5 so as to surround it along the outer shape of the electronic component, the three sides of the lands 7 and 8 are surrounded by the solder resist film. Is done. As a result, it is possible to obtain the effect of further raising the electronic components while suppressing the sinking of the electronic components into the lands 7 and 8, and the molten solder between the electronic components 1A, 1B, 1C and the lands 7 and 8. Can be accommodated more. Therefore, even if a mask that collectively supplies the solder paste to the printed wiring board 5 is used, it is possible to prevent the solder from sticking out from the side end faces 11 and 12 of the electrodes 3 and 4 to the outside in the longitudinal direction X. Therefore, it is possible to mount the electronic components 1A, 1B, and 1C on the printed wiring board 5 at a high density while ensuring the joining strength at the solder joining portion 9.

In the first embodiment, the composition of the solder paste used to form the solder joint 9 is Sn-3.0Ag-0.5Cu, that is, Ag has a mass of 3.0% and Cu has a mass of 0.5%. It is preferable that Sn is the balance. The viscosity of the solder paste is preferably 170 Pa · s to 210 Pa · s (25 ° C.). Further, the average particle size of the solder in the solder paste is preferably about φ20 μm. The flux content in the solder paste is preferably 10.5% by mass to 12.5% by mass.

In the first embodiment, as shown in FIG. 2A, the length L ₂ of the electronic components 1A, 1B, 1C in the longitudinal direction X is equal to or less than the length L ₁ of the opening 61 in the longitudinal direction X. 0.894 ≤ L ₂ / L ₁ ≤ 1. Further, the width of the opening 61 in the lateral direction Y and the width of the electronic components 1A, 1B, 1C in the lateral direction Y are the same.

FIG. 3B is a plan view of a part of the wireless communication module 100, which is an example of the printed circuit board according to the first embodiment. In FIG. 3B, two electronic components 1A and 1B adjacent to each other along the longitudinal direction X of the electronic components are shown among the plurality of electronic components. The two electronic components 1A and 1B shown in FIG. 3B are of the same size that allow deviation within the tolerance range. When the printed wiring board 5 is viewed in a plan view, the shortest distance in the longitudinal direction X between the side end surface 11 of one electrode of the two electronic components facing each other and the side end surface 12 of the other electrode of the two electronic components. Rx is equal to or less than the width W in the lateral direction Y of the substrate 2 of the electronic component. That is, two electronic components 1A and 1B arranged adjacent to each other along the longitudinal direction X of the electronic components are mounted on the printed wiring board 5 at high density.

Since the electronic components 1A and 1B are chip components of an inductor or a capacitor, the areas of the side end faces 11 and the side end faces 12 are the side surfaces 13, 14, 15, 16, the bottom surfaces 17, 19, and the top surfaces 18, 20. Larger than each area. Therefore, when the solder paste is melted, the molten solder adheres to the side end faces 11 and 12 more than the side surfaces 13, 14, 15 and 16 of the electronic components 1A and 1B. That is, it is difficult to arrange the electronic components at a higher density (so that the distance between the electronic components becomes smaller) in the longitudinal direction X than in the lateral direction Y of the substrate 2 in FIG. 3 (b).

Therefore, in the first embodiment, the length of the solder overhanging from the side end faces 11 and 12 in the longitudinal direction X is controlled by adjusting the shapes of the lands 7 and 8 with respect to the area of the side end faces 11 and 12. ..
In FIG. 2A, a land extending the solder length extending _outward from the side end faces 11 of the electronic components 1A and 1B to the outside in the longitudinal direction X from the side end faces 11 of the electronic components 1A and 1B to the inside of the longitudinal direction X. Let _LiA be the length of 7, that is, the length of the portion where the land 7 is not covered with the solder resist and is exposed in the longitudinal direction X. The length of the solder extending _outward from the side end faces 12 of the electronic components 1A and 1B in the longitudinal direction X is LOB, and the length of the land 8 extending inward in the longitudinal direction X from the side end faces 12 of the electronic components 1A and 1B, that is, the longitudinal length. When the length of the portion where the land 8 is exposed without being covered with the solder resist in the direction X is _LiB , the effect of reducing the overhang length of the solder can be obtained by satisfying the following relationship as the connection structure. ..
0.183 ≤ L _OA / L _iA ≤ 0.309
0.183 ≤ L _OB / L _iB ≤ 0.309

This relationship is derived from the following simulation results.
The electronic components 1A and 1B were used as 0402 size inductors or capacitors. That is, the area S _DA of the side end surface 11 of the electrode 3 and the area S _DB of the side end surface 12 of the electrode 4 are 0.04 mm ² , respectively. The material of the insulating substrate 10 was FR-4. The opening 61 of the solder resist film 6 has a size of 0.4 mm × 0.2 mm so as to surround the outer shape of the electronic component when the printed wiring board 5 is viewed in a plan view.
At this time, the relationship between the area S _LA of the land 7 and the area S _LB of the land 8 and the overhang length (maximum value) of the solder from the side end surface 11 of the electrode 3 and the side end surface 12 of the electrode 4 in the longitudinal direction X is established. , Computer simulated.
The width of each land 7 and 8 in the lateral direction Y was fixed at 0.2 mm, and the length in the longitudinal direction X was changed between 0.1 mm and 0.2 mm for simulation. The length of each land 7 and 8 in the longitudinal direction X is changed and analyzed by thermo-fluid simulation. The state in which the shape change of the solder is eliminated is defined as the joint shape, and the overhang length of the solder from the side end faces 11 and 12 is determined. Calculated. The volume of solder to be melted was fixed at 1 million μm ³ for each land 7 and 8, and the distance between the upper surface of each land 7 and 8 and the bottom surfaces 17 and 19 of each electrode 3 and 4 was fixed at 20 μm.

FIG. 4 is a graph showing the simulation results in the first embodiment.
FIG. 4 illustrates the calculation result of the overhang length of the solder for S _LA / S _DA . Since the solder overhang length on the side end surface 12 has the same result as the side end surface 11, the solder overhang length on the side end surface 11 side will be described.

From FIG. 4, it can be seen that when S _LA / S _DA <0.6, the solder overhang length from the side end surface 11 hardly changes. That is, it can be seen that there is no effect of reducing the overhang length of the solder. On the other hand, when S _LA / S _DA is 0.66 or more, it can be seen that the overhang length of the solder can be reduced by 10% or more as compared with the case of S _LA / S _DA = 0.5. Therefore, the S _LA / S _DA is preferably 0.66 or more. When S _LA / S _DA = 0.66, the length _LiA of the land 7 of the electronic components 1A and 1B was 132.5 μm. Further, a thermo-fluid simulation was performed with _LiA = 132.5 μm, and the solder length overhanging from the side end surface 11 to the outside in the longitudinal direction X was found to be 41 μm. Therefore, when the electronic components 1A and 1B are 0402 size inductors or capacitors, the upper limit of _LOA / _LiA is 0.309 (41 / 132.5).

On the other hand, the larger the value of S _LA / S _DA , the smaller the overhang length of the solder can be. However, if the width of each land 7 and 8 in the lateral direction Y is set to 0.2 mm and each land 7 and 8 is extended in the longitudinal direction X until the land 7 and the land 8 come into contact with each other, the longitudinal direction of each land 7 and 8 is extended. Contact with a length of X of 0.2 mm. In this case, S _LA / S _DA and S _LB / S _DB are 1.00. That is, if S _LA / S _DA <1.00 and S _LB / S _DB <1.00, the lands 7 and 8 are separated from each other.

Further, in the subtract method, which is a general method for manufacturing a printed circuit board, if the distance between lands is too close, the lands come into contact with each other, and a short circuit defect is likely to occur. The distance between the lands 7 and the lands 8 that are unlikely to cause a short circuit defect is 0.05 mm or more. Therefore, if the width of each land 7 and 8 in the lateral direction Y is 0.2 mm and the space between the lands 7 and 8 is secured by 0.05 mm, the length of the land 7 and 8 in the longitudinal direction X is 0.175 mm. Become. Further, a thermo-fluid simulation was performed with _LiA = 175 μm, and the solder length extending from the side end surface 11 to the outside in the longitudinal direction X was obtained and found to be 32 μm. Therefore, when the electronic components 1A and 1B are 0402 size inductors or capacitors, the lower limit of LOA / _LiA is 0.183 ( _32/175 ). The S _LA / S _DA at this time was 0.88.

From the above, in the first embodiment, it is more preferable that 0.66 ≦ S _LA / S _DA and 0.66 ≦ S _LB / S _DB . As a result, it is possible to more effectively reduce the overhang length of the solder from the side end faces 11 and 12, and it is possible to more effectively prevent short circuit defects.
Further, in order to prevent short circuit defects, the overhang length of the solder from the side end faces 11 and 12 may be reduced, but in order to maintain the joining strength, some solder is required on the side end faces 11 and 12. Therefore, it is more preferable that S _LA / S _DA ≤ 0.88 and S _LB / S _DB ≤ 0.88.

Further, the relationship of the ratio of the preferable area of the portion 111 to the area of the opening 61 of the solder resist film 6 shown in FIG. 3A is preferably 12.5% or more and 34% or less. Within this range, the effect of reducing the overhang length of the solder can be obtained. This relationship is obtained by dividing the area of the exposed portion 111 of the insulating substrate 10 located between the lands 7 and 8 by the area of the opening 61. 12.5% is the calculation result of (0.4 × 0.2-0.175 × 0.2 × 2) / (0.4 × 0.2). 34% is the calculation result of (0.4 × 0.2-0.1325 × 0.2 × 2) / (0.4 × 0.2).

Looking at the graph in FIG. 4, it can be seen that there is an inflection point in the overhang length of the solder with respect to S _LA / S _DA . It is considered that this is because the overhanging shape of the solder can be approximated as a circle. In the first embodiment, since the solder joint portion 9 has a filletless structure, the solder adhering to the electrode 3 has a substantially circular shape, and a part of the radius of the circle can be considered as the solder overhang length. Therefore, if the area of the land 7 is increased, that is, the amount of moving a part of the circular solder to the bottom surface of the electrode 3 is set to a certain amount or more, the radius of the solder circle can be increased. Since the radius of the solder circle becomes large, the solder moves inward in the longitudinal direction X on the outside of the side end surface 11 of the electronic component 1, and it becomes possible to reduce the overhang length of the solder from the side end surface 11.

From the above results, when the electronic components 1A and 1B are, for example, 0402 size capacitors or inductor chip components, the distance Rx between the two electronic components 1A and 1B adjacent to each other in the longitudinal direction X shown in FIG. 3B is 0. If it is 15 mm, the shortest distance D is calculated to be 150- (41 × 2) = 68 μm.

Further, instead of a simulation, two electronic components 1A and 1B were actually mounted on the printed wiring board 5 and the shortest distance D was measured.
The distance Rx between the two electronic components 1A and 1B adjacent to each other in the longitudinal direction X was set to 0.15 mm. The size of each of the lands 7 and 8 was 0.1325 mm × 0.2 mm, and the S _LA / S _DA was 0.66. The shortest distance D at this time was measured.
After the amount of solder supplied as the solder paste in the printing process was heated and melted, a sample of about 1 million μm ³ was extracted, and the shortest distance D was measured and found to be 59 μm.
There is a difference between the simulation result and the actual measurement result. Actually, there are external crossings of the electronic components 1A and 1B, mounting positions of the electronic components 1A and 1B, and misalignments of the electronic components 1A and 1B due to self-alignment that occur when the solder melts.
Therefore, it is considered that the actual shortest distance D is narrower than the calculated shortest distance D. As described above, even if the actual shortest distance D varies, there is no joining defect in the solder joint portion 9, and the two electronic components 1 are arranged close to each other with a distance of 0.15 mm in the longitudinal direction X. Even in that case, short-circuit defects did not occur.

From the above simulation and experimental results, when the distance Rx in the longitudinal direction X of the two electronic components 1 is 0.15 mm, it is possible to prevent the occurrence of joint defects and short circuit defects. Then, it was confirmed that high-density mounting with a distance Rx in the longitudinal direction X of 0.15 mm or less is possible. Therefore, according to the present embodiment, small electronic components 1A and 1B can be mounted at high density between the electronic components 1A and 1B and the printed wiring board 5 without providing an additional member such as a spacer.
Although the case where the sizes of the electronic components 1A and 1B are 0402 size has been described, the present invention is not limited to this, and the electronic components 1A and 1B may be smaller than the 0402 size, for example, 0201 size. That is, high-density mounting is possible when the distance Rx in the longitudinal direction X of the substrates 2 of the two electronic components 1 facing each other is equal to or less than the width W in the lateral direction Y of the substrate 2.
Further, as shown in FIG. 9, by reducing the solder overhang length Lo in the longitudinal direction X, it is possible to control the solder overhang length Lo'in the lateral direction Y to be equal to or less than the same.
Even when the three electronic components 1 are actually arranged and mounted close to each other with an interval of 0.15 mm in the longitudinal direction X and 0.15 mm in the lateral direction Y, a short circuit defect occurs. There was no.
Therefore, in the three electronic components 1, the electrons satisfy Ry ≧ Rx as the relationship between the distance Rx of the two electronic components 1 close to the longitudinal direction X and the distance Ry of the two electronic components 1 close to the lateral direction Y. High-density mounting is possible by arranging component 1.

[Second Embodiment]
The printed circuit board according to the second embodiment will be described. FIG. 5 is a perspective view of the electronic component 1D according to the second embodiment and a part of the printed wiring board 5. For convenience of explanation, FIG. 5 illustrates a state before mounting the electronic component 1D on the printed wiring board 5. For convenience of illustration, FIG. 5 shows only one electronic component 1D, but at least two electronic components of the same type as the electronic component 1D are arranged adjacent to each other along the longitudinal direction X of the electronic component 1D. There is. In the second embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In the first embodiment, the case where the electronic component is a chip component which is a capacitor or an inductor has been described, but in the second embodiment, the case where the electronic component 1D is a chip component which is a resistor will be described. The planar size of the resistor is the same as that of the capacitor and the inductor, but the length in the thickness direction and the structure of the electrode are different from those of the capacitor and the inductor.

The electronic component 1D is provided at the electrode 3A, which is the first electrode provided at the first end portion, and the second end portion, out of the two ends of the substrate 2A and the longitudinal direction X of the substrate 2A which is a predetermined direction. The second electrode, the electrode 4A, is included.

As described in the first embodiment, the printed wiring board 5 has a solder resist film 6 provided on the main surface 110 of the insulating substrate 10. The solder resist film 6 is formed with an opening 61 for exposing the lands 7 and 8. In the second embodiment, as in the first embodiment, the length of the opening 61 of the solder resist film 6 in the longitudinal direction X is substantially the same as the length of the electronic component 1D in the longitudinal direction X. Further, as in the first embodiment, the width of the opening 61 in the lateral direction Y and the width of the electronic component 1D in the lateral direction Y are the same.

In the second embodiment, the electronic component 1D is a chip component that is a resistor. The electrode 3A has a side end surface 11A, a bottom surface 17A, and an upper surface 18A. Each surface 11A, 17A, 18A may be a flat surface or a curved surface. The electrode 3A does not have a side surface that is located on the outermost side when viewed along the lateral direction Y described in the first embodiment and intersects with the lateral direction Y. The side end surface 11A is a surface that is located on the outermost side when viewed along the longitudinal direction X and intersects the longitudinal direction X. That is, the normal with respect to the side end surface 11A points in the longitudinal direction X. The electrode 4A has a side end surface 12A, a bottom surface 19A, and an upper surface 20A. Each surface 12A, 19A, 20A may be a flat surface or a curved surface. The electrode 4A does not have a side surface that intersects with the lateral direction Y, which is located on the outermost side when viewed along the lateral direction Y described in the first embodiment. The side end surface 12A is a surface that is located on the outermost side when viewed along the longitudinal direction X and intersects the longitudinal direction X. That is, the normal with respect to the side end surface 12A points in the longitudinal direction X. As described above, when the electronic component 1D is a chip component of a resistor, the solder adheres to the electrodes 3A and 4A on each of the three surfaces. Therefore, more solder adheres to the side end faces 11A and 12A.

Therefore, in the second embodiment, the length of the solder overhanging from the side end faces 11A, 12A in the longitudinal direction X is controlled by adjusting the shapes of the lands 7 and 8 with respect to the area of the side end faces 11A, 12A. ..
The solder length extending outward from the side end surface 11A of the electronic component 1D in the longitudinal direction X is _{LOA, and the length LiA of} the land 7 extending inward in the longitudinal direction X from the side end surface 11A of the electrode 3A of the electronic component 1D. .. The solder length extending outward from the side end surface 12A of the electronic component 1D in the longitudinal direction X is _{LOB, and the length LiB of} the land 8 extending inward in the longitudinal direction X from the side end surface 12A of the electrode 4A of the electronic component 1D. At the time, as the connection structure, the effect of reducing the overhang length of the solder can be obtained by satisfying the following relationship.
0.177 ≤ L _OA / L _iA ≤ 0.309
0.177 ≤ L _OB / L _iB ≤ 0.309

This relationship is derived from the following simulation results.
The electronic component 1D was used as a 0402 size resistor. That is, the area SDA of the side end surface _11A in the electrode 3A and the area _SDB of the side end surface 12A in the electrode 4A are 0.026 mm ² , respectively. That is, the area S _DA of the side end surface 11A and the area S _DB of the side end surface 12A are each less than 0.05 mm ² . The material of the insulating substrate 10 was FR-4. The opening 61 of the solder resist film 6 has a size of 0.4 mm × 0.2 mm so as to surround the outer shape of the electronic component when the printed wiring board 5 is viewed in a plan view.
At this time, the relationship between the area S _LA of the land 7 and the area S _LB of the land 8 and the overhang length (maximum value) of the solder in the longitudinal direction X from the side end surface 11A of the electrode 3A and the side end surface 12A of the electrode 4A is established. , Computer simulated.

The width of each land 7 and 8 in the lateral direction Y was fixed at 0.2 mm, and the length in the longitudinal direction X was changed between 0.1 mm and 0.2 mm for simulation. The length of each land 7 and 8 in the longitudinal direction X is changed, and the analysis is performed by thermo-fluid simulation. Calculated. The volume of solder to be melted was fixed at 1 million μm ³ for each land 7 and 8, and the distance between the upper surface of each land 7 and 8 and the bottom surfaces 17A and 19A of the electrodes 3A and 4A was fixed at 20 μm.

FIG. 6 is a graph showing the simulation results in the second embodiment.
FIG. 6 illustrates the calculation result of the overhang length of the solder for S _LA / S _DA . Since the solder overhang length on the side end surface 12A side has the same result as that on the side end surface 11A, the solder overhang length on the side end surface 11A side will be described.

From FIG. 6, it can be seen that when S _LA / S _DA <0.92, the solder overhang length from the side end surface 11A hardly changes. That is, it can be seen that there is no effect of reducing the overhang length of the solder. On the other hand, when S _LA / S _DA is 1.02 or more, it can be seen that the overhang length of the solder can be reduced by 10% or more as compared with the case of S _LA / S _DA = 0.76. Therefore, the S _LA / S _DA is preferably 1.02 or more. When S _LA / S _DA = 1.02, the length _LiA of the land 7 of the electronic component 1D was 132.5 μm. Further, a thermo-fluid simulation was performed with _LiA = 132.5 μm, and the solder length overhanging from the side end surface 11A to the outside in the longitudinal direction X was found to be 41 μm. Therefore, when the electronic component 1D is a resistor of 0402 size, the upper limit of _LOA / _LiA is 0.309 (41 / 132.5).

On the other hand, the larger the value of S _LA / S _DA , the smaller the overhang length of the solder can be. However, if the width of each land 7 and 8 in the lateral direction Y is set to 0.2 mm and each land 7 and 8 is extended in the longitudinal direction X until the land 7 and the land 8 come into contact with each other, the longitudinal direction of each land 7 and 8 is extended. Contact with a length of X of 0.2 mm. In this case, S _LA / S _DA and S _LB / S _DB are 1.54. That is, if S _LA / S _DA <1.54 and S _LB / S _DB <1.54, the lands 7 and 8 are separated from each other.

Further, in the subtract method, which is a general method for manufacturing a printed circuit board, if the distance between lands is too close, the lands come into contact with each other, and a short circuit defect is likely to occur. The distance between the lands 7 and the lands 8 that are unlikely to cause a short circuit defect is 0.05 mm or more. Therefore, if the width of each land 7 and 8 in the lateral direction Y is 0.2 mm and the space between the lands 7 and 8 is secured by 0.05 mm, the length of the land 7 and 8 in the longitudinal direction X is 0.175 mm. Become. Further, a thermo-fluid simulation was performed with _LiA = 175 μm, and the solder length extending from the side end surface 11A to the outside in the longitudinal direction X was obtained and found to be 31 μm. Therefore, when the electronic component 1D is a resistor of 0402 size, the lower limit of LOA / _LiA is 0.177 ( _31/175 ). The S _LA / S _DA at this time was 1.35.

From the above, in the second embodiment, 1.02 ≦ S _LA / S _DA and 1.02 ≦ S _LB / S _DB are more preferable. As a result, it is possible to more effectively reduce the overhang length of the solder from the side end faces 11A and 12A, and it is possible to more effectively prevent short circuit defects.
Further, in order to prevent short circuit defects, the overhang length of the solder from the side end faces 11A and 12A may be reduced, but in order to maintain the bonding strength, some solder is required on the side end faces 11A and 12A. Therefore, it is more preferable that S _LA / S _DA ≤ 1.35 and S _LB / S _DB ≤ 1.35.

From the above results, when the electronic component 1D is, for example, a chip component of a resistor of 0402 size, if the distance Rx of the two electronic components 1D adjacent to each other in the longitudinal direction X is 0.15 mm, the shortest distance D is calculated to be 150. -41 x 2 = 68 μm.

From the above simulation and experimental results, when the distance Rx in the longitudinal direction X of the two electronic components 1D is 0.15 mm, it is possible to prevent the occurrence of joint defects and short circuit defects. Then, it was confirmed that high-density mounting with a distance Rx in the longitudinal direction X of 0.15 mm or less is possible. Therefore, according to the present embodiment, small electronic components 1D can be mounted at high density between the electronic component 1D and the printed wiring board 5 without providing an additional member such as a spacer.
Although the case where the size of the electronic component 1D is 0402 size has been described, the present invention is not limited to this, and the electronic component 1D may be smaller than the 0402 size, for example, 0201 size. That is, high-density mounting is possible when the distance Rx in the longitudinal direction X of the substrate 2 of the two electronic components 1D facing each other is equal to or less than the width W in the lateral direction Y of the substrate 2.

[Third Embodiment]
Next, the printed circuit board according to the third embodiment will be described. FIG. 7 is a schematic diagram of a joint structure of an electronic component and a printed wiring board in a wireless communication module which is an example of a printed circuit board according to a third embodiment. In the third embodiment, the same components as those of the first embodiment and the second embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In the first embodiment, the length L ₂ of the electronic components 1A, 1B, 1C in the longitudinal direction X is equal to or less than the length L ₁ of the opening 61 in the longitudinal direction X, that is, 0.894 ≦ L ₂ / L ₁ ≦ 1. However, the case is not limited to this. The relationship of 0.894 ≤ L ₂ / L ₁ ≤ 1.120 may be satisfied. In the third embodiment, the length L ₂ of the electronic component 1E in the longitudinal direction X is longer than the length L ₁ of the opening 61 in the longitudinal direction X, that is, 1 <L ₂ / L ₁ ≦ 1.120. ..

The thickness of the solder resist film 6 is, for example, 10 μm to 35 μm. The electrode 3 of the electronic component 1E is bonded to the land 7 exposed by the opening 61 of the solder resist film 6 at the solder bonding portion 9. The electrode 4 of the electronic component 1E is bonded to the land 8 exposed by the opening 61 of the solder resist film 6 at the solder bonding portion 9. The width of the opening 61 in the lateral direction Y is 0.2 mm, which is the same as the width of the electronic component 1E in the lateral direction Y. As described above, the opening 61 is formed to have a size hidden by the electronic component 1E in a plan view. That is, when the printed wiring board is viewed in a plan view, the entire opening 61 overlaps with the electronic component 1E.

In the third embodiment, the size of the opening 61 of the solder resist film 6 of the printed wiring board 5 is 0.36 mm × 0.2 mm so that the opening 61 is hidden from the electronic component 1E.
Other than that, the analysis was performed by thermo-fluid simulation under the same conditions as in the first embodiment.

FIG. 8 is a graph of simulation results according to the third embodiment. FIG. 8 shows the simulation results of the overhang length of the solder from the side end surface 11 for each of the joining structures of the first embodiment and the third embodiment. FIG. 8 illustrates the overhang length of the solder in the case of S _LA / S _DA = 0.6 6 in both the first embodiment and the third embodiment. As shown in FIG. 8, in the first embodiment, the overhang length of the solder was 41.5 μm, and in the third embodiment, the overhang length of the solder was 33.5 μm.

From this result, it was confirmed that the overhang length of the solder can be reduced in the third embodiment as compared with the first embodiment. Therefore, according to the third embodiment, the small electronic components 1 can be mounted at high density between the electronic component 1E and the printed wiring board 5 without providing an additional member such as a spacer.

As described above, according to the third embodiment, the end portion of the electronic component 1E in the longitudinal direction X is located on the solder resist film 6. Therefore, in the reflow step, the molten solder is repelled by the solder resist film 6 and moves to the lands 7 and 8, and also moves in the thickness direction by the thickness of the solder resist film 6. Therefore, the overhang length of the solder adhering to the side end faces 11 and 12 can be further reduced. Therefore, the two electronic components 1E adjacent to each other in the longitudinal direction X can be arranged closer to each other at a distance equal to or less than the width in the lateral direction Y of the substrate 2. Although the case of the electronic component 1E has been described in the third embodiment, the same effect can be obtained even with the electronic component 1A.

The present invention is not limited to the embodiments described above, and many modifications can be made within the technical idea of the present invention.

In the above-mentioned first to third embodiments, the case where the lands 7 and 8 have a rectangular shape has been described, but the present invention is not limited to this. For example, the lands 7 and 8 may have an elliptical shape or a convex shape. Further, the via conductor may be arranged directly under the lands 7 and 8. This makes it easy to pull out the wiring during high-density mounting.

In the first to third embodiments described above, the case where the width of the opening in the lateral direction and the width of the electronic component in the lateral direction are the same has been described, but the present invention is not limited to this. There may be a difference of within ± 0.05 mm between the width of the opening in the lateral direction and the width of the electronic component in the lateral direction. That is, the width of the opening in the lateral direction and the width of the electronic component in the lateral direction may be the same within a predetermined tolerance.

In the above-mentioned first to third embodiments, the case where the end portions 73, 74, 83, 84 in the lateral direction of the conductor patterns 70, 80 are covered with the solder resist film has been described, but the present invention is not limited thereto. .. The ends 73, 74, 83, 84 may not be covered with the solder resist film. At that time, the width of the lands 7 and 8 in the lateral direction may be the same as the width of the opening in the lateral direction, or may be shorter than the width of the opening in the lateral direction.

1A, 1B, 1C ... Electronic components, 3 ... Electrode (1st electrode), 4 ... Electrode (2nd electrode), 5 ... Printed wiring board, 6 ... Solder resist film, 7 ... Land (1st land), 8 ... Land (2nd land), 10 ... Insulated substrate, 61 ... Opening, 70 ... Conductor pattern (1st conductor pattern), 80 ... Conductor pattern (2nd conductor pattern), 100 ... Wireless communication module (printed circuit board), 110 ... Main surface, 600 ... Digital camera (electronic device), X ... Longitudinal direction (predetermined direction)

Claims (15)

A first chip component and a second chip component having a first electrode and a second electrode at the end in the longitudinal direction, each having a length of L2 in the longitudinal direction and a length of W in the lateral direction.
The insulating substrate, the solder resist film having an opening provided on the insulating substrate, and the first land and the second electrode exposed at the opening are bonded to the first land and the second electrode, respectively, via solder. A printed wiring board with 2 lands and
It is an electronic module equipped with
The first chip component and the second chip component are inductors or capacitors arranged adjacent to each other along the longitudinal direction so that the longitudinal directions of the first chip component and the second chip component coincide with each other.
The distance Rx between the first chip component and the second chip component in the longitudinal direction is W or less.
When the length of the opening in the longitudinal direction is L1, the L1 and the L2 are
Satisfy 0.894 ≤ L2 / L1 ≤ 1.120,
The length of the first land in the longitudinal direction is _LiA , the length of the second land is _LiB , the thickness of the solder on the side end surface of the first electrode is _LOA , and the thickness of the solder on the side end surface of the second electrode. When is _LOB ,
Satisfy 0.183 ≤ L _OA / L _iA ≤ 0.309 and 0.183 ≤ L _OB / L _iB ≤ 0.309.
An electronic module characterized by that. When the area of the side end surface of the first electrode is S _DA , the area of the side end surface of the second electrode is S _DB , the area of the first land is S _LA , and the area of the second land is S _LB.
Satisfy the relationship of 0.66 ≤ S _LA / S _DA ≤ 0.88 and 0.66 ≤ S _LB / S _DB ≤ 0.88.
The electronic module according to claim 1. A first chip component and a second chip component having a first electrode and a second electrode at the end in the longitudinal direction, each having a length of L2 in the longitudinal direction and a length of W in the lateral direction.
The insulating substrate, the solder resist film having an opening provided on the insulating substrate, and the first land and the second electrode exposed at the opening are bonded to the first land and the second electrode, respectively, via solder. A printed wiring board with 2 lands and
It is an electronic module equipped with
The first chip component and the second chip component are resistors arranged adjacent to each other along the longitudinal direction so that the longitudinal directions of the first chip component and the second chip component coincide with each other.
The distance Rx between the first chip component and the second chip component in the longitudinal direction is W or less.
When the length of the opening in the longitudinal direction is L1, the L1 and the L2 are
Satisfy 0.894 ≤ L2 / L1 ≤ 1.120,
The length of the first land in the longitudinal direction is _LiA , the length of the second land is _LiB , the thickness of the solder on the side end surface of the first electrode is _LOA , and the thickness of the solder on the side end surface of the second electrode. When is _LOB ,
Satisfy 0.177 ≤ L _OA / L _iA ≤ 0.309 and 0.177 ≤ L _OB / L _iB ≤ 0.309.
An electronic module characterized by that. When the area of the side end surface of the first electrode is S _DA , the area of the side end surface of the second electrode is S _DB , the area of the first land is S _LA , and the area of the second land is S _LB.
Satisfy 1.02 ≤ S _LA / S _DA ≤ 1.35 and 1.02 ≤ S _LB / S _DB ≤ 1.35.
The electronic module according to claim 3. The distance Rx between the first chip component and the second chip component is 0.15 mm or less.
The electronic module according to any one of claims 1 to 4. The area of each of the side end surface of the first electrode and the side end surface of the second electrode is less than 0.05 mm ² .
The electronic module according to any one of claims 1 to 5. The first chip component and the second chip component are chip components having a size of 0402 or less.
The electronic module according to claim 6. When the printed wiring board is viewed in a plan view, the area of each of the first land and the second land is 40% or less of the area of the opening.
The electronic module according to any one of claims 1 to 7. The longitudinal length L2 of the first chip component and the second chip component is longer than the longitudinal length L1 of the opening.
The electronic module according to any one of claims 1 to 8. When the printed wiring board is viewed in a plan view, the entire opening overlaps with each of the first chip component and the second chip component.
The electronic module according to any one of claims 1 to 9. The printed wiring board has an antenna and a wireless communication IC.
The electronic module according to any one of claims 1 to 10, wherein the electronic module is a communication module. 11. The electronic module according to claim 11, wherein the antenna and the wireless communication IC are provided on the surface of the insulating substrate on the side where the solder resist film is provided. With the housing
An electronic device comprising the electronic module according to any one of claims 1 to 12 provided in the housing. 13. The aspect of the electronic module, wherein the surface on the side where the solder resist film is provided is arranged closer to the housing than the surface on the side where the solder resist film is not provided. Electronic devices listed in. The electronic device according to claim 14 , wherein the electronic device is a camera.

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